Widespread contamination of surface water chloride is an emerging environmental concern. Consequently accurate and cost-effective methods are needed to estimate chloride along all river miles of potentially contaminated watersheds. Here we introduce a Bayesian Maximum Entropy (BME) space/time geostatistical estimation framework that uses river distances, and we compare it with Euclidean BME to estimate surface water chloride from 2005 to 2014 in the Gunpowder-Patapsco, Severn, and Patuxent subbasins in Maryland. River BME improves the cross-validation R2 by 23.67% over Euclidean BME, and river BME maps are significantly different than Euclidean BME maps, indicating that it is important to use river BME maps to assess water quality impairment. The river BME maps of chloride concentration show wide contamination throughout Baltimore and Columbia-Ellicott cities, the disappearance of a clean buffer separating these two large urban areas, and the emergence of multiple localized pockets of contamination in surrounding areas. The number of impaired river miles increased by 0.55% per year in 2005–2009 and by 1.23% per year in 2011–2014, corresponding to a marked acceleration of the rate of impairment. Our results support the need for control measures and increased monitoring of unassessed river miles.

Microplastic fibers (MP) from textile weathering and washing are increasingly being recognized as environmental pollutants. The majority of studies on the bioavailability and effects of microplastic focused on small polystyrene spherical plastic particles, while less data are available for fibers and for other materials besides polystyrene. We investigated the ingestion and effects of ground polyethylene terephthalate (PET) textile microfibers (length range: 62–1400 μm, width 31–528 μm, thickness 1–21.5 μm) on the freshwater zooplankton crustacean Daphnia magna after a 48 h exposure and subsequent 24 h of recovery in MP free medium and algae. The majority of ingested fibers by D. magna were around 300 μm, but also some very large twisted MP fibers around 1400 μm were found inside the gut. Exposure to these fibers results in increased mortality of daphnids after 48 h only in the case where daphnids were not pre-fed with algae prior to experiment, but no effect was found when daphnids were fed before the experiments. Regardless of the feeding regime, daphnids were not able to recover from MP exposure after additional 24 h incubation period in a MP free medium with algae. The uptake and effects of PET textile MP on D. magna are presented here for the first time.

Atmospheric concentrations of organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs) and neutral per- and polyfluoroalkyl substances (PFAS) have been measured at Villum Research Station, Station Nord (North Greenland) in the period 2008–2013. Atmospheric concentrations of OCPs at the same site have been previously reported for the years 2008–2010. The detection frequency and the average concentrations of OCPs have not significantly changed since the previous study. PBDE congeners (∑13PBDEs) were measured for the first time in North Greenland at concentrations similar to those observed for other remote sites, confirming that these compounds are ubiquitous in the Northern Hemisphere. The ∑13PBDEs concentration ranged from not detected (n.d.) to 6.26 pg m⁻³. The BDE congeners found in more than 30% of the samples were BDE-17, BDE-28, BDE-47, BDE-71, BDE-99 and BDE-100. Also for neutral PFAS we present for the first time a multiyear series of measurements for North Greenland. The average sum of the seven measured neutral PFAS (∑7PFAS) ranged from 1.82 to 32.1 pg m⁻³. The most abundant compound was 8:2 FTOH (44% of ∑7PFAS), followed by 6:2 FTOH and 10:2 FTOH. Perfluoroalkyl sulfonamides (FOSA) and perfluoroalkyl sulfonamidoethanols (FOSE) were also detected but at much lower concentrations than FTOHs.Temporal trends were investigated for all measured compounds but no significant trend in concentration was observed. Monthly average concentrations for the six years were calculated for each compound and the seasonal variation was investigated. Some OCPs and FTOHs showed seasonal variations, and in most cases a maximum was found during summer.

This research evaluates the analytical capabilities of a field portable X-ray fluorescence spectrometer (pXRF) for the measurement of contaminated soil samples using a matrix-matched calibration. The calibrated pXRF generated exceptional data quality from the measurement of ten soil reference materials. Elemental recoveries improved for all 11 elements post-calibration with reduced measurement variation and detection limits in most cases. Measurement repeatability of reference values ranged between 0.2 and 10% relative standard deviation, while the majority (82%) of reference recoveries were between 90 and 110%. Definitive data quality, the highest of the US EPA's three level quality ranking, was achieved for 15 of 19 elemental datasets. Measurement comparability against inductively coupled plasma atomic emission spectrometry (ICP-AES) values was excellent for most elements (e.g, r2 0.999 for Mn and Pb, r2 > 0.995 for Cu, Zn and Cd). Parallel measurement of reference materials revealed ICP-AES and ICP-MS measured Ti and Cr poorly when compared to pXRF. Individual recoveries of soil reference materials by both ICP-AES and pXRF showed that pXRF was equivalent to or better than ICP-AES values for all but two elements (Ni, As). This study demonstrates pXRF as a suitable alternative to ICP-AES analysis in the measurement of Ti, Cr, Mn, Fe, Cu, Zn, Sr, Cd, and Pb in metal-contaminated soils. Where funds are limited, pXRF provides a low-cost, high quality solution to increasing sample density for a more complete geochemical investigation.

Atmospheric Pb deposition was reconstructed using peat cores from bogs in the vicinity of Flin Flon, Manitoba, Canada, home to a zinc refinery and copper smelter. The Sask Lake (SL4-1) core was collected 85 km NW of Flin Flon and Kotyk Lake (KOL) 30 km NE. The distribution of Sr and U show that both profiles are predominantly minerotrophic (ie groundwater-fed), but the Pb concentration profile shows that Pb was received exclusively from the atmosphere. Graphs of 208Pb/206Pb against 206Pb/207Pb document atmospheric Pb contamination dating from the early to mid-1800’s, well before the start of metallurgical processing (in 1930) and attributable to long-range atmospheric transport from other regions of North America. Industrial activities at Flin Flon clearly affected the concentrations, enrichment factor (calculated using Sc), and accumulation rates of Pb, but it is the similarity in isotopic composition, and contrast with crustal values (206Pb/207Pb ca. 1.20 to 1.22) which makes the connection to the Flin Flon ores. The KOL samples dating from 1925–1976 CE have a 206Pb/207Pb of 1.032 ± 0.002 (n = 11) which approach the values for the Flin Flon ores (206Pb/207Pb = 1.008). But even at SL4-1, the peat samples dating from 1925–1976 CE have a 206Pb/207Pb of 1.061 ± 0.022 (n = 18) which is well below the corresponding ratio of Canadian leaded gasoline (206Pb/207Pb = ca. 1.15). The SL4-1 site too, therefore, was clearly impacted by Pb from mining and metallurgy, despite the distance (88 km) from Flin Flon and being predominantly upwind. These two bogs not only provide the chronology of atmospheric Pb deposition for the past decades, but suggest that the extent of contamination may have been underestimated by previous studies.

Transport of environmental pollutants through porous media is influenced by colloids. Co-transport of As(V) and soil colloids at different pH were systematically investigated by monitoring breakthrough curves (BTCs) in saturated sand columns. A solute transport model was applied to characterize transport and retention sites of As(V) in saturated sand in the presence of soil colloids. A colloid transport model and the DLVO theory were used to reveal the mechanism and hypothesis of soil colloid-promoted As(V) transport in the columns. Results showed that rapid transport of soil colloids, regulated by pH and ionic strength, promoted As(V) transport by blocking As(V) adsorption onto sand, although soil colloids had low adsorption for As(V). The promoted transport was more significant at higher concentrations of soil colloids (between 25 mg L−1 and 150 mg L−1) due to greater blocking effect on As(V) adsorption onto the sand surfaces. The blocking effect of colloids was explained by the decreases in both instantaneous (equilibrium) As adsorption and first-order kinetic As adsorption on the sand surface sites. The discovery of this blocking effect improves our understanding of colloid-promoted As transport in saturated porous media, which provides new insights into role of colloids, especially colloids with low As adsorption capacity, in As transport and mobilization in soil-groundwater systems.

The Kuril Islands region is considered promising for development of salmon aquaculture. There are 41 salmon fish hatcheries in the Sakhalin Island and the Kuril Islands, 34 of them are hatcheries of the chum. Therefore, concentrations of six elements (Zn, Cu, Cd, Pb, As, and Hg) were determined in chum salmon were caught in this region. The contents of toxic elements (Cd, Pb, As, and Hg) don't exceed their maximum permissible concentrations (MPC) according to the Russian sanitary standards, but concentration of Pb are closely to MPC. Increased concentrations of Pb in wild chum have the natural origin. The unusual conditions of the Western Pacific are formed under the influence such factors as volcanism and upwelling.

The occurrence and fate of 48 pharmaceuticals and personal care products (PPCPs) in three wastewater treatment plants (WWTPs) located in different urbanization areas in Xiamen, China was investigated over one year. Results showed that PPCPs were widely detected, but the major PPCPs in the influent, effluent, and sludge were different. Spatial and seasonal variations of PPCP levels in the influent and sludge were observed. The removal efficiencies for most PPCPs were similar among the three WWTPs, although they employed different biological treatment processes. Furthermore, the mass loadings per inhabitant of most pharmaceuticals had a positive correlation with the urbanization levels, indicating that most pharmaceutical usage was higher in the urban core compared to the suburban zones. The total mass loadings of all the 48 PPCPs in the effluent and waste sludge showed close proportions, which suggested the importance of proper waste sludge disposal to prevent a large quantity of PPCPs from entering the environment.

The focus of the present study was to find the relationship between concentrations of bisphenol A (BPA), 4-tert-octylphenol (OP) and 4-nonylphenol (NP) in zooplankton and seasonal changes in the composition and biomass of particular zooplankton taxa in the Gulf of Gdansk (Southern Baltic) in the years 2011–2012. Assays of BPA, OP and NP in water and zooplankton samples were performed using the HPLC/FL system. High mean concentrations of the studied compounds, determined in spring (405.9 (BPA); 25.7 (OP); 111.2 (NP) ng g−1 dw), can be linked to the high proportion of meroplankton in that season. Rotifera also had an influence on the rise in concentrations of the studied compounds but to a lesser degree, while the lowest concentrations (determined in summer) can be associated with the high participation of Copepoda and Cladocera in zooplankton biomass. It was also observed that juvenile forms can be more susceptible to accumulating endocrine disrupting compounds (EDCs). This is indicated by the positive correlation between BPA concentration in zooplankton and the proportion of Copepoda nauplii biomass in spring (r = 0.90; p < 0.05). In most cases, greater zooplankton biomass accumulated higher concentrations and loads of the studied compounds. With biomass growth (to 123.32 μg m−3), the bioconcentration factor also rose (to max 46.1·103), demonstrating that unlike typical hydrophobic compounds the studied EDCs do not become “diluted” in zooplankton biomass. The highest BPA concentrations from all compounds may be connected with anthropogenic sources located in the coastal zone.

Wind-driven sediment resuspension exerts significant effects on the P behavior in shallow lake ecosystems. In this study, a comprehensive dynamic phosphorus (P) model that integrates hydrodynamic, wind wave and sediment transport is proposed to assess the importance of internal P cycling due to sediment resuspension on water column P levels. The primary contribution of the model is detailed modeling and rigorous coupling of sediment and P dynamics. The proposed model is applied to predict the P behavior in the shallow Taihu Lake, which is the third largest lake in China, and quantitatively estimate the effects of wind waves and lake currents on P release and distribution. Both the prevailing southeast winds in summer and northwest winds in winter are applied for the simulation, and different wind speeds of 5 m/s and 10 m/s are also considered. Results show that sediment resuspension and the resulting P release have a dominant effect on P levels in Taihu Lake, and likely similar shallow lakes. Wind-driven waves at higher wind speeds significantly enhance sediment resuspension and suspended sediment concentration (SSC). Total P concentration in the water column is also increased but not in proportion to the SSC. The different lake circulations resulting from the different prevailing wind directions also affect the distribution of suspended sediment and P around the lake ultimately influencing where eutrophication is likely to occur. The proposed model demonstrates that internal cycling in the lake is a dominant factor in the lake P and must be considered when trying to manage water quality in this and similar lakes. The model is used to demonstrate the potential effectiveness of remediation of an area where historical releases have led to P accumulation on overall lake quality.